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UNITED STATES DAILY ATMOSPHERIC SURVEY
the bend of their parabolic course, at about latitude thirty. They
have for years furnished a fruitful theme for the thoughts of the
investigator.
For twenty-seven years the forecasters of the Weather Bureau
have studied the inception, development, and progression of these
different classes of atmospheric disturbances. From a knowledge
personally gained by many years service as an official forecaster,
I do not hesitate to express the opinion that we long since reached
the highest degree of accuracy in the making of forecasts possible
to be attained with surface readings. It is patent that we are
extremely ignorant of the mechanics of the storm, of the opera
tions of those vast yet subtle forces in free air which give incep
tion to the disturbance and which supply the energy necessary
to continue the same.
Having long realized this, I determined at once, on coming to
the control of the United States Weather Bureau, to systemat
ically attack the problem of upper-air exploration, with the hope
ultimately of being able to construct a daily synoptic weather
chart from simultaneous readings taken in free air at an altitude
of not less than one mile above the earth, as it appeared to me
that previous plans for investigating the upper air by means of
free and uncontrollable balloons, by observers in balloons, or by
independent kite stations were of little value in getting the in
formation absolutely necessary to improve our methods of fore
casting. Simultaneous observations at a uniformly high level
from many kite stations was the plan I inaugurated for the pros
ecution of this important investigation. Professor Marvin was
assigned to the difficult task of devising appliances and making
instruments, and I am pleased to say that we have improved on
kite-flying to such an extent that apparatus is now easily sent
up to a height of one mile in only a moderate wind. We have
made an automatic instrument that, while weighing less than
two pounds, will record temperature, pressure, humidity, and
wind velocity. Before next spring we expect to have not less
than twenty stations placed between the Rocky mountains and
the Atlantic ocean taking daily readings at an elevation of one
mile or more.
We shall then construct a chart from the high-level readings
obtained at these twenty stations and study the same in connec
tion with the surface chart made at the same moment. Being
thus able to map out not only the vertical gradients of tempera
ture, humidity, pressure, and wind velocity, but the horizontal